Point of purchase terminals or other terminals which receive both confidential and nonconfidential information are known. Terminals for debit card transactions are known where certain information is confidential, such as PINs (personal identification number), and other information is nonconfidential, such as the purchase price of a product. Other confidential information could include the account balance whereas license plate identification for a gas purchase would be nonconfidential.
Initial terminals had two entry keypads, one of which could be for nonconfidential information and having its own separate display and the other being a dedicated keypad for confidential information, such as the PIN. Typically, the keypad for inserting confidential information could be separated and the user could actually shield the keypad during the entry of the confidential information. Although the keypad for the confidential information typically had a display, only prompts came up on the display and the confidential information was not displayed.
There has been a need to reduce the space occupied by such point of purchase terminals and there are now point of purchase terminals having a single display and a single keypad for receiving both confidential and nonconfidential information. Unfortunately, the degree of security which was previously present with a separate keyboard for confidential information has not been provided in these combined confidential and nonconfidential information keyboards and there is a higher risk that these devices could be tampered with to reveal confidential information of the user. The entire system is based on the premise of the PIN being maintained in a confidential manner, as this is in effect the signature of the user and his authorization. There remains a need to provide a system which reduces the size of the point of purchase terminal while maintaining a high degree of security with respect to the entry of confidential information and the operation of the terminal such that it can only operate in a secure manner with respect to prompts which would produce the entry of confidential information.